Atossa Therapeutics (ATOS) H.C. Wainwright 26th Annual Global Investment Conference 2024 summary

Lead asset overview and differentiation

• (Z)-endoxifen is a direct active metabolite of tamoxifen, offering efficacy without the unwanted byproducts of tamoxifen metabolism.

• Functions as both a SERM and SERD, blocking and degrading estrogen receptors, providing a more potent anti-estrogen effect.

• Clinical trials show vasomotor side effects occur in less than 10% of patients, a significant reduction compared to tamoxifen.

Breast density reduction program

• Historical data links breast density reduction with a 63% decrease in cancer incidence over five years.

• Low-dose (Z)-endoxifen achieves higher active blood levels than standard tamoxifen dosing, supporting efficacy at lower doses.

• Ongoing phase 2 trial expects to show significant density reduction versus placebo, with results anticipated in the second half of the year.

• Reducing breast density may improve cancer detection and reduce reliance on costly imaging like MRI and ultrasound.

• New FDA requirements for reporting breast density will increase awareness and potential demand for therapies.

Market opportunity and next steps

• Approximately 10 million women annually in the US are identified with high breast density, with the top 20% accounting for most interval cancers.

• Next steps include large trials targeting interval cancers in high-density women, aiming for a 60% reduction in cancer incidence.